Apparatus for generating pulsed impingement jets in freezers

Abstract

An apparatus provides pulsed impingement jets to a sub-chamber within an impingement hood of a freezer, and includes a blower having an inlet and an outlet at an interior of the freezer; a duct having a first end in fluid communication with the outlet and a second end opening into the sub-chamber; and a flow valve disposed in the duct proximate the second end opening, the flow valve movable in repetitive open and closed positions for providing repetitive, discrete pulses of the impingement jets from the second end opening of the duct into the sub-chamber.

What is claimed is: 
     
       1. An apparatus for providing pulsing, to impingement jets of a cryogen gas that are discharged by a main blower through impingement holes in an impingement plate from and out of a sub-chamber within an impingement hood of a freezer that contains said cryogen gas for freezing a food product, comprising:
 a pressure blower having an inlet and an outlet at an interior of the freezer and external to the impingement hood; 
 a distribution pipe having a first end in fluid communication with the outlet of the pressure blower, and a second end extending to an opening in the impingement hood for fluid communication with the sub-chamber; and 
 a flow valve disposed in the distribution pipe proximate the opening, the flow valve movable in repetitive open and closed positions for providing repetitive, discrete pulsing, to the impingement jets, from the opening at the second end of the distribution pipe into the sub-chamber. 
 
     
     
       2. The apparatus of  claim 1 , wherein the cryogen gas is a substance selected from the group consisting of nitrogen, carbon dioxide, cold air, and other cold gas. 
     
     
       3. The apparatus of  claim 2 , further comprising at least one nozzle opening at the interior of the freezer for providing the substance to said interior. 
     
     
       4. The apparatus of  claim 3 , wherein the at least one nozzle opening is at the sub-chamber. 
     
     
       5. The apparatus of  claim 1 , further comprising an actuator operatively associated with the flow valve to provide the repetitive open and closed movement of the flow valve in the distribution pipe. 
     
     
       6. The apparatus of  claim 1 , further comprising a port in the distribution pipe for accessing an interior of the distribution pipe. 
     
     
       7. The apparatus of  claim 1 , further comprising a shroud mounted at the interior of the freezer for protecting the blower. 
     
     
       8. The apparatus of  claim 7 , wherein the shroud further comprises a lid constructed and arranged to be movable for permitting access to the blower and an internal space of the shroud. 
     
     
       9. The apparatus of  claim 1 , wherein the flow valve comprises at least one vane in the distribution pipe mounted for the repetitive open and closed positions within the distribution pipe.